Japanese Patent Application Laid-Open No. 10-66677 discloses a conventional technique of incorporating an imaging device into an instrument for dental treatment.
In Japanese Patent Application Laid-Open No. 10-66677, an optical fiber imaging bundle and a CCD camera are incorporated into an instrument. One end of the optical fiber imaging bundle is provided with an objective lens system that is arranged near a treatment tool and a work area. Light emitted from a target site of imaging is guided through the objective lens and the optical fiber imaging bundle to the CCD camera, thereby capturing an image of the site.
Techniques similar to this are disclosed in Japanese Patent No. 3067854 and Japanese National Publication of Translation No. 4-503320.
Many sites cannot be viewed directly when they are treated within an oral cavity. Sites that are not directly visible include those that cannot morphologically be viewed due to the shape of a tooth or the shape inside the oral cavity, and those that cannot be viewed with the eyes of the operator of an operation (dentist). The operator should treat these invisible sites, or sites that are hard to be viewed.
The techniques disclosed in Japanese Patent Application Laid-Open No. 10-66677, Japanese Patent No. 3067854 and Japanese National Publication of Translation No. 4-503320 realize imaging of some of these invisible sites, or sites that are hard to be viewed.
However, in the techniques disclosed in Japanese Patent Application Laid-Open No. 10-66677, Japanese Patent No. 3067854 and Japanese National Publication of Translation No. 4-503320, imaging is conducted from a direction tilted from the axial direction of a cutting tool such as a dental drill. So, images of many sites cannot be captured by normal use thereof.
It is assumed for example that a hole is defined in a tooth, and then the deep part of the hole is treated, like as in the treatment of a pulp cavity in a tooth or in root canal treatment. In this case, the tooth itself, for example the outer edge of the crown of the tooth gets in the way, thereby making it difficult to illuminate the pulp cavity or the root canal and capture an image thereof. In order to capture an image of the pulp cavity or the root canal, light reflected from the pulp cavity or the root canal should be received. However, the reflected light is interrupted by the tooth itself, thereby making it impossible to receive light required for imaging. Or, the tooth itself may get in the way, so the emitted light cannot reach the pulp cavity or the root canal in the first place.
The structure according to the techniques disclosed in Japanese Patent Application Laid-Open No. 10-66677, Japanese Patent No. 3067854 and Japanese National. Publication of Translation No. 4-503320 contains an image guide such as an optical fiber for guiding light from a site being treated to an imaging element and the like. This means these techniques require a relatively expensive image guide, and the complicated structure of the instrument itself.
In view of the above, the present invention is intended to more reliably capture an image of a site being treated even during the treatment thereof, while realizing a simplified structure by eliminating an expensive image guide.